How do sound waves travel through outer space?
Sound or pressure waves can travel through space because space is not empty, but in many instances is filled with a warm, thin plasma of charged and neutral atoms. Interplanetary space is constantly swept by the solar ‘wind’, and pressure and density disturbances propagate outwards from their origin on the solar surface at the typical sound speed of the solar wind which is a few hundred kilometers per second given its temperature and density through out the solar system. These pressure disturbances are, in effect, sound waves.
